Natural fresh cream prepared from milk has been used for production of whipped creams for confectioneries and desserts. However recently, compounded whipped creams in which some of the milk fat contained in the fresh cream is replaced with vegetable oil and also pure-vegetable whipped creams in which all fat is replaced with vegetable oil are developed and now becoming mainstream products. Such whipped creams are cost-effective and superior, particularly for example, in storage stability of the raw solution before whipping, processability during whipping and processability after whipping. In addition, such a foamable oil-in-water emulsified oil composition for whipped cream containing a vegetable oil (raw solution before whipping) can be produced by emulsification of fresh cream and various vegetable oils additionally with improvers such as emulsifiers and thickeners. It is thus possible to change the texture and physical properties of the whipped cream significantly by modification of the composition of these raw materials, in particular of the oils. In the recent trend particularly toward lighter texture, emphasis is directed to their mouth melting characteristics.
The oil used in such a foamable oil-in-water emulsified oil composition for whipped creams is for example a lauric acid-type oil such as coconut oil or palm kernel oil. The lauric acid-type oil is a sharp melting fat that is superior in mouth melting characteristics and refreshing. The lauric acid-type oils have been used together with their hardened oils in production of foamable oil-in-water emulsified oil compositions for whipped creams, mainly of foamable oil-in-water emulsified oil compositions for whipped creams having a smaller oil content (hereinafter, referred to as “light creams”). However, conventional foamable oil-in-water emulsified oil compositions for whipped creams, which contain much hardened lauric acid-type oils, easily become harder over time after whipping, thus making the processability such as topping thereof more difficult over time.
In addition, because a light cream has a smaller oil content, its whipping characteristics change significantly when the temperature of the raw solution before whipping increases by several degrees. Excessively higher temperature often resulted in insufficient incorporation of air bubbles and gave inappropriate overrun.
Foamable oil compositions for creams containing oils ester-exchanged with palm oil or a lauric acid-type oil and also containing a lauric acid-type oil were proposed for improvement of whip physical properties and mouth melting characteristics after whipping (Patent Document 1). However, it was difficult to suppress the change over time in hardness of the composition after whipping.
Also proposed was an oil composition for whipped creams, in which: the content of lauric acid residues in all triglycerides in the oil is 30 to 60 mass % with respect to the total amount of the fatty acid residues; the content of triglycerides containing fatty acid residues having a carbon atom number of 42 to 49 is 20 to 45 mass % with respect to the total amount of the triglyceride; and the content of triglycerides containing fatty acid residues having a carbon atom number of 50 to 62 is 4 to 15 mass % with respect to the total amount of the triglyceride (Patent Document 2). The composition shows favorable stability in shape in normal temperature range (approximately 15 to 35° C.) and gives normal temperature-distribution whipped creams (foamable oil-in-water emulsified fat) that show favorable mouth melting characteristics and are superior in long-term emulsion stability during storage at normal temperature and resistant to hardening when stored at normal temperature. However, the properties are lost in the chilled region.
Also proposed was an oil-in-water emulsified oil composition containing an ester-exchanged oil prepared by ester exchange between at least one oil (1) selected from the group consisting of lauric acid-type oils, fractionated lauric acid-type oils, and extremely hardened lauric acid-type oils; and an oil containing saturated fatty acids having a carbon number of 16 or more and unsaturated fatty acids having a carbon number of 16 or more at a particular rate (Patent Document 3). Because of the composition above, the composition is favorable in mouth melting characteristics, whipping characteristics such as foaming and whip physical properties such as stability in shape, but it is not possible to suppress the change in hardness over time after whipping sufficiently.
There was a study on suppression of the change in hardness over time after whipping and an oil for light creams containing SUS-type triglycerides and a lauric acid-type oil was proposed (Patent Document 4). Although there is no problem in suppression of the change in hardness over time after whipping in the case of the whipped cream obtained from the cream oil, since increase of the temperature of the raw solution by several degrees leads to decrease of the overrun due to insufficient air bubble incorporation and loss of normal whipping characteristics, the whipped cream demanded stricter temperature control and was thus lower in processability.